[The necrotizing enteritis by Clostridium perfringens type C in piglets: practical observations, control and epidemiology].

Necrotizing enteritis in piglets is caused by the spore-forming anaerobe Clostridium perfringens type C. The pathology is believed to be due to the production of beta-toxin by the agent and the infection tends to persist in affected herds despite appropriate hygiene measures. During the period 1989 to 2001, 35 outbreaks were observed in 15 herds in a limited geographic region in northwestern Switzerland in the canton of Fribourg. Initial outbreaks of acute disease were followed by chronic manifestations of necrotizing enteritis in eleven herds. Since clinical symptoms in case of chronic necrotizing enteritis and of mixed infections were rather non-specific, diagnosis in all herds was confirmed by gross pathological analysis, intestinal histology and bacteriological culture. After initial evaluation in 135 litters (1500 piglets), metaphylaxis consisted of penicillin for outbreaks of acute disease or of amoxycillin-clavulanic acid pending results of laboratory confirmation. Vaccination with a C. perfringens toxoid vaccine (Gletvax 6, also containing E. coli pilus antigens) together with penicillin chemoprophylaxis was used in 2400 litters (27,000 piglets). In 12 to 17% of litters disease recurred during this combined prophylaxis. Necrotizing enteritis persisted in all affected herds throughout the follow-up period.